Q1) One of the implications of quantum mechanics is that
1) extremely small particles can never be observed.
2) Newtonian physics was a mistake.
3) the act of observation may alter the entity being observed.
Q2) Two one-dimensional traps have infinite potential energy at
their walls. Trap A has width L and trap B has width 2L. For which
value of the quantum number n does a particle in trap B have the
same energy as a particle in the ground state of trap A?
1) n = 1
2) n = 2
3) n = 3
4) n = 4
5) n = 5
Q3) An electron is in a one-dimensional trap with zero potential
energy in the interior and infinite potential energy at the walls. The
ratio E3/E1 of the energy for n = 3 to that for n = 1 is:
1) 1/3
2) 1/9
3) 3/1
4) 9/1
5) 1/1
Q4) Each of the following particles is confined to an infinite well,
and all four wells have the same width:
(a) an electron,
(c) a deuteron, and
(b) a proton,
(d) an alpha particle.
Rank their zero-point energies, greatest first. The particles are
listed in order of increasing mass.
1) all tie
2) a, b, c, d
3) d, c, b, a
4) none of the above
Q5) The diagram shows the energy levels for an electron in a
certain atom. Of the transitions shown, which represents the
emission of a photon with the most energy?
Q6) Rank the following pairs of quantum states for an electron
confined to an infinite well according to the energy differences
between the states, greatest first:
(a) n = 3 to n = 1,
(b) n = 5 to n = 4,
(c) n = 4 to n = 3.
1) a, b, c
4) b, a, c
2) a, b=c
5) none of the above
3) b, c, a
Q7) An electron in an atom initially has an energy 7.5 eV above
the ground state energy. It drops to a state with an energy of 3.2 eV
above the ground state energy and emits a photon in the process.
The momentum of the photon is:
1) 1.7 × 10−27 kg m/s
2) 2.3 × 10−27 kg m/s
3) 4.0 × 10−27 kg m/s
4) 5.7 × 10−27 kg m/s
5) 8.0 × 10−27 kg m/s
Q8) An electron trapped in a one-dimensional infinite
well is in its fourth excited state. How many different
ways can the electron return to its ground state?
1) 6
2) 7
3) 8
4) 9
5) 10
Q9) Suppose that an electron trapped in a onedimensional infinite well has a ground state energy of
10 eV. Can the electron absorb a photon whose energy
is 40 eV?
1) yes
2) no
Q10) An electron in the ground state absorbs a photon with a
wavelength of 103 nm and becomes excited. Which of the
following is an allowed decay process?
1) The electron emits a 93-nm photon, then a 640-nm photon.
2) The electron emits a 656-nm photon, then a 122-nm photon.
3) The electron emits a 103-nm photon, then a 728-nm photon.
Q11) An electron is trapped in a one-dimensional infinite
potential well and is in its fifth excited state. How many
points of (a) zero probability and (b) maximum probability
does its matter wave have?
1)
2)
3)
4)
5)
(a) 5
(a) 6
(a) 6
(a) 7
(a) 7
(b) 5
(b) 5
(b) 6
(b) 6
(b) 7
Q12) An electron is in a one-dimensional trap with zero potential
energy in the interior and infinite potential energy at the walls. A
graph of its wave function ψ(x) versus x is shown. The value of
quantum number n is:
1) 0
2) 2
3) 4
4) 6
5) 8
Q13) The figure shows three infinite potential wells of widths L, 2L,
and 3L; each contains an electron in the state for which n = 10. Rank
the wells according to (a) the number of maxima for the probability
density of the electron and (b) the energy of the electron, greatest
first.
1) (a) all tie
2) (a) all tie
3) (a) a, b, c
4) (a) c, b, a
5) all tie
(b) c, b, a
(b) a, b, c
(b) a, b, c
(b) c, b, a
Q14) An electron is trapped in a rectangular box with
Lx = Ly = Lz = L. In multiples of h2/8mL2, what is the energy of the
third excited state?
1) 10
2) 11
3) 12
4) 13
5) none of the above
Q15) A rectangular corral of widths Lx = L and Ly = 2L contains
an electron. In multiples of h2/8mL2, what is the difference
between the energies of its second and third excited states?
1) 3/4
2) 1
3) 5/4
4) 7/4
5) none of the above
Q16) The figure shows the energy levels for an electron “trapped”
in a finite potential energy well 450 eV deep. If the electron is in
the ground state and absorbs a photon, which of the following
could not be the wavelength of the absorbed photon?
1) 14.6 nm
2) 7.25 nm
3) 4.84 nm
4) 2.84 nm
Q17) A particle in a certain finite potential energy well can have any
of five quantized energy values and no more. Which of the following
would allow it to have any of six quantized energy levels?
1) Increase the momentum of the particle
2) Decrease the momentum of the particle
3) Decrease the well width
4) Increase the well depth
5) Decrease the well depth
Q18) An electron is in a one-dimensional well with finite potential
energy barriers at the walls. The matter wave:
1) is zero at the barriers
2) is zero everywhere within each barrier
3) is zero in the well
4) extends into the barriers
5) is discontinuous at the barriers
Q19) Which one of the following will result in an electron transition
from the n = 4 level to the n = 7 level in a hydrogen atom?
1) emission of a 0.28 eV photon
2) emission of a 0.57 eV photon
3) emission of a 0.85 eV photon
4) absorption of a 0.28 eV photon
5) absorption of a 0.57 eV photon
Q20) A hydrogen atom is in the third excited state. To what state
should it jump to (a) emit light with the longest possible
wavelength, (b) emit light with the shortest possible wavelength,
and (c) absorb light with the longest possible wavelength?
1)
2)
3)
4)
5)
(a) n = 3
(a) n = 3
(a) n = 2
(a) n = 1
(a) n = 1
(b) n = 1
(b) n = 1
(b) n = 1
(b) n = 2
(b) n = 3
(c) n = 5
(c) n = 
(c) n = 3
(c) n = 
(c) n = 5
Q21) An electron is in the n = 3 state of hydrogen. What
wavelength photon(s) can the electron absorb to break free of the
hydrogen atom?
1) 91.2 nm
2) 822 nm
3) 900 nm
4) two of the above
5) all of the above
Q22) Determine the energy of the photon emitted when the
electron in a hydrogen atom undergoes a transition from the n = 8
level to the n = 6 level.
1) 0.17 eV
2) 0.21 eV
3) 0.36 eV
4) 0.57 eV
5) 13.4 eV
Q23) What is the longest wavelength in the Paschen series of
atomic spectra?
1) 8.204 × 10-7 m
2) 1.875 × 10-6 m
3) 2.216 × 10-6 m
2) 5.522 × 10-6 m
3) 6.756 × 10-5 m